Theory of anodic stripping voltammetry at wall-jet electrodes. Simulation of spatially differential stripping and redeposition phenomena
Theory of anodic stripping voltammetry at wall-jet electrodes. Simulation of spatially differential stripping and redeposition phenomena
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DOI：
10.1021/jp9720810
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发表时间：
1998-01-01
影响因子：
3.3
通讯作者：
Brett, CMA
中科院分区：
文献类型：
--
作者：
Ball, JC;Compton, RG;Brett, CMA
基于时间相关向后隐式方法的数值模拟被用来发展在流体动力学条件下使用汞薄膜壁喷射电极进行阳极溶出伏安法的理论。的峰形示出是高度敏感的电解质流速和电位扫描速率。模拟允许可视化的浓度在溶液中，并在整个伏安电位扫描的膜。它们揭示了在空间上不均匀的方式与流诱导电极的中心被耗尽之前，并在较低的正电位比，电极的径向末端的膜剥离。此外，对于具有类似于分析实践中所采用的流动和扫描速率参数的电化学可逆系统，可以看出，从电极中心氧化的材料可以在更靠近电极边缘的径向距离处再沉积，其中扩散层更厚，之后在更正的电势下的电势扫描中再氧化。
Numerical simulations based on the time dependent backward implicit method are used to develop the theory of anodic stripping voltammetry carried out under hydrodynamic conditions using mercury thin film wall-jet electrodes. The peak shape is shown to be highly sensitive both to electrolyte flow rate and to the potential sweep rate. The simulations permit visualization of concentrations both in solution and in the film throughout the voltammetric potential sweep. They reveal the film to be stripped in a spatially nonuniform fashion with the flow inducing the center of the electrode to be depleted before, and at less positive potentials than, the radial extremities of the electrode. Moreover for electrochemically reversible systems with flow and sweep rate parameters similar to those employed in analytical practice it is seen that material oxidized from the electrode center can become redeposited at radial distances closer to the electrode edge where the diffusion layer is thicker, before being re-oxidized later on in the potential sweep at more positive potentials.